Fluid treating filter

ABSTRACT

An improved filter for treating fluids utilizing a frame of unitary construction. The frame is constructed from a sheet of expanded substantially rigid material having solid sections disposed between sections of expanded material. The frame is adapted for folding into a box-like configuration with the solid portions forming end walls of the box. Filter media, such as fiberglas, is disposed within the enclosed box.

Unite States Patent 1191 v 1111 3,793,692

Tate et al. Feb. 26, 1974 FLUID TREATING FILTER 2,138,874 12/1938 Myers55 1310. 31 2,597,927 5/1952 E d 55/528 x [75] Inventors: Tate; whenJackson 2,989,145 6 1961 0262;; 29/1635 F Louisville, y- 3,724,6714/1973 Tate 5511310. 31 [73] Assigneez American Air Film, Company Inc"2,850,269 9/1958 Bohanon 55 519 Louisville, Ky.

22 Filed; Dem 2 1972 Primary ExaminerSamih N. Zaharna A r rE F.F.Cl tt'[2]] Appl- No 314,368 8818 an xammer ave 1 Related US. Application Data[62] Division of Ser. No. 111,303, Feb. l, 1971, [57] ABSTRACTabandoned.

An improved filter for treating fluids utilizing a frame [52] 29/163'529/611, 55/518, of unitary construction. The frame is constructed fromSS/DIG- 3 I 1 210/484 a sheet of expanded substantially rigid materialhaving [Sl] Int. Cl. Bold 27/08 Solid Sections disposed between sectionsof expanded [58] Field of Search S5/DIG' material. The frame is adaptedfor folding into a box- 55/528; 29/163-5 210/484 485 like configurationwith the solid portions forming end walls of the box. Filter media, suchas fiberglas, is dis- [56] References Cited posed within the enclosedbox.

UNITED STATES PATENTS 3,429,434 2/1969 Hickin 55/519 4 Claims, 8 DrawingFigures mammal 3.7s3,e92,

SHEET 1 UF 4 PAiimEnnzszsmm saw u or 4 INVENTOR. 205mm. uAcKsm BY JOHN 5r 0% g, w flrromm I FLUID TREATING FILTER CROSS REFERENCE TO RELATEDAPPLICATIONS The present invention is a division of copendingapplication, Ser. No. 111,303, filed Feb. I, 1971 by John E. Tate andRobert L. Jackson now abandoned.

BACKGROUND OF THE INVENTION In the conditioning of air in airconditioners, furnaces, and the like, the air to be processed is usuallypassed through a filter to remove particles of dust and other foreignmatter. For many years filters utilizing fibrous material, such asfiberglas, as a filtering media have been used for removing theseundesirable particles from the air. These filters come in many sizes andshapes and are constructed by many different methods. One of the mostcommon type of filters in use today is one in which a basic core ofcontinuous glass fibers bound together by a resinous coating is confinedbetween two closely perforated sheets of bright brass. The perforatedsheets are generally scrap from bottle plants and contain close circularorifices placed as closely together as possible. The circular orificesaccount for nearly 90% of the total she et area. The fiberglas media andthe two closely perforated sheets of bright brass are held together byan inwardly facing U-channel constructed of fiber board or similarmaterial. The side pieces of fiber board are either stapled together attheir ends to hold them in tact with the perforated sheets or they areattached to the perforated sheets with an adhesive. Further, in somecases a narrowed metal strip is added to extend diagonally across eachface of the perforated sheet to give extra strength.

SUMMARY OF THE INVENTION In the present invention, it is recognized thatit is desirable to provide a filter for treating fluids which isinexpensive, more durable, and more easily fabricated than the filtersprepared by the present accepted methods. Furthermore, it is desirableto have filters for fluid treating which have inherently increasedstrength within the filtering zone without requiring additional steps,such as, adding rigid strips diagonally across the face of theperforated sheets. It is also desirable to have a filter which hasincreased strength along its borders so that the filter will not weakenduring heavy use.

The present invention advantageously provides a straight forwardarrangement for manufacturing a filter for treating fluids which iseconomical, easily fabricated, and contains a minimum number of parts.The present invention further provides an improved frame for supportingfilter media. The present invention also provides a filter for treatingfluids having improved strength and durability in operating position.

Various other features of the present invention will become obvious tothose skilled in the art upon reading the disclosure set forthhereinafter.

More particularly, the present invention provides a fluid treatingfilter comprising a filter media and a flowthrough box-like configuredsupport frame of one piece integral and unitary construction framed as aunit to include fluid impervious end walls and integral front and backretaining screens, said frame being adapted to enclose said filtermedia. In addition the present invention may include sidewalls adaptedto fit and engage said support frame.

It is to be understood that the description of the examples of thepresent invention given hereinafter are not by way of limitation andvarious modifications within the scope of the present invention willoccur to those skilled in the art upon reading the disclosure set forthhereinafter.

Referring now to the Figures:

FIG. 1 is a perspective view of a filter of the present invention;

FIG. 2 is a perspective view of a unitary frame assembly according toone advantageous embodiment of the present invention prior to beingfolded into a box-like configuration;

FIG. 3 is a perspective view of a unitary frame assembly of FIG. 2 in apartially folded position;

FIG. 4 is an exploded perspective view of a filter of the presentinvention;

F IG. 5 is a perspective view of a unitary frame assembly of anotherembodiment of the present invention prior to being folded into abox-like configuration;

FIG. 6 is a perspective view of a unitary frame assembly of FIG. 5 in apartially folded position;

FIG. 7 discloses a schematic flow diagram of an inventive method formaking a new and useful filter of the present invention; and,

FIG. 8 discloses a perspective schematic flow diagram for adding sidesto a filter constructed according to the inventive method of FIG. 7.

Referring to FIG. 1 of the drawings, a filter assembly in accordancewith one embodiment of the present invention is disclosed. The filterassembly includes a unitary frame assembly 1, filter media 3, anddetachable sides 2 and 1 l. The frame assembly 1 is bent into a boxlikeconfiguration with filter media 3 disposed within the confines of thebox. Detachable sides 2 and 11 which advantageously are of U-shapedcross-section, are adapted to outer fit and enclose the sides of theunitary frame assembly I. A latch member 9, shown in the Figures as anindented tongue, is provided on the sides 2 and 11 for engaging groove10 (FIG. 4) of the ends 7 and 8 (FIG. 4).

' The unitary frame assembly 1 is illustrated in FIG. 2 in unfoldedform. The unitary frame assembly 1 includes solid ends 7 and 8 andretaining screens 4 and 6. The unitary frame assembly 1, as illustratedin the present embodiment, is a modification of a sheet of expandedmetal wherein an expanded metal producing machine (not shown) hasexpanded only selected portions of a sheet of metal leaving otherselected portions as solid metal. By selectively expanding only specificsections of the metal sheet and leaving other selected portions solid, afilter frame assembly having front and back retaining screens 4 and 6with ends 7 and 8 is produced. In the illustration in FIGS. 2 and 3 thescreens 4 and 6, and the ends 7 and 8 are constructed so that when bentat the junctions of the screens 4 and 6 with the ends 7 and 8, abox-like configuration is the result.

FIG. 3 illustrates the unitary frame assembly 1 in a position whereinthe end 7 has been bent upwards at its juncture with screen 6 and end 8has been bent upwards at its juncture with screen 6. Filter media 3,which advantageously can be of fiberglas and adapted to fit within theconfines of the unitary frame assembly 1 when in a box-likeconfiguration, is shown in place in the frame assembly 1 prior to thebending in a sidewards direction of screen 4 at its juncture with end 8.

The free edge of screen 4 is adapted to mate with the free edge of end7, as illustrated in FIG. 4, when the unitary frame assembly 1 is bentinto its box-like configuration. FIG. 4 further illustrates theengagement of the detachable sides 2 and 11 with frame assembly 1. Sides2 and 11 are adapted to fit the frame assembly 1 and latch members 9 andgrooves 10, as mentioned previously, are provided as the means forengaging and disengaging the sides 2 and 1] from the ends 7 and 8.

FIGS. 5 and 6 of the drawings illustrate another preferred unitary frameassembly 1 of the present invention. FIG. 5 illustrates the unitaryframe assembly 1 in unfolded form. The unitary frame assembly 1 includessolid ends 7 and 8 and retaining screen 4 and 6. Screen 6 is furtherprovided with extending sides 12.

FIG. 6 illustrates the unitary frame assembly 1 of FIG. 5 in a partiallyfolded position wherein end 8 has been bent upwards at its juncture withscreen 6, and extending sides 12 have been bent upwards at theirjuncture with screen 6. Filter media 3, adapted to fit within theconfines of the unitary frame assembly 1 when in a box-likeconfiguration, is shown in place in the frame assembly 1 prior to thebending in a sidewards direction of screen 4 at its juncture with end 8.The free edges of screen 4 are adapted to mate with the free edges ofextending sides 12 and end 7 (not shown). Detachable sides 2 and 11 maybe added to engage with frame as sembly 1 to give added support andrigidity to the sides.

Referring to FIG. 7 of the drawings, in carrying out the presentinvention, sheet metal is fed from roll 21 onto endless conveyor 22.Sheet metal from roll 21 is fed by conveyor 22 and guide rolls 23 to ametal expanding machine 24. Expanding die 26 is provided in machine 24for expanding the metal. Further, expanding die 26 is set to raise atspecifically set intervals so that at selected spacings on the sheetmetal, the metal is left in tact as it passes under the die 26.

Expanded metal in the metal expanding machine 24 is then conveyed to aslitter 27 wherein the expanded metal is slit into sections of selectedlengths. The expanded metal sections are then passed to a first formingmachine 29. Guide rolls 28 are provided to guide the expanded metalsections into the machine 29 wherein upwardly extending ram 31,downwardly extending ram 32 and upwardly extending ram 33 form theexpanding metal section into a semi-formed unitary frame I assembly. Thesemi-formed assembly is then transferred to endless conveyor 38 where itis conveyed to filter media adding means 34 wherein filter media isadded to the semi-formed unitary frame assembly.

The assembly containing the filter media is then conveyed to a secondforming machine 36 wherein horizontally extending ram 37 urges thevertically extending top section of the frame assembly into a horizontalposition thereby completing the formation of a box-like frame withfilter media confined therein.

FIG. 8 illustrates the addition of detachable sides to the filterproduct of FIG. 7 by transferring the filter product of FIG. 7 toendless conveyor 39 which in turn conveys the product to horizontallyextending capping means 41 wherein detachable sides are added to theproduct.

Other modifications of the aforementioned method, such as adding filtermedia to the expanded metal prior to the first forming machine, and thenforming the frame assembly in one step instead of two as illustrated,are contemplated without departing from the scope of the presentinvention. However, in practice, it has been found that semi-forming theassembly, then adding the filter media prior to the final forming step,is preferred since the semi-formed assembly lines up the sides andenables for easy addition of the 'filter media.

In the preparation of a filter of the instant invention, the unitaryframe assembly 1 may be fabricated by modifying expanded metal asillustrated, as well as plastics and similar materials. Latch member 9,illustrated as a tongue in the aforementioned example, may be any meansfor engaging sides 2 and 11, such as, groove 10, with the assembly 1.Further, latching means may be provided for on the unitary frameassembly 1 instead of the sides 2 and 11 with a latch receiving means onthe sides, without departing from the scope of the invention.

It will be realized that other changes may be made to the specificembodiment shown and described without departing from the principles andspirit of the present invention.

We claim:

1. A method of making a fluid treating filter comprising the steps of:passing a sheet of metal through a means for expanding a selectedportion of said sheet of metal; cutting said sheet to a desiredconfiguration; adding a selected quantity of filter media to said cutsheet; and forming said sheet into a unitarily constructed box-likeconfiguration, the selected expanded portions of said sheet beingpositioned as a back and front support for said filter media and thenonexpanded portion of said sheet being positioned as end walls for saidfilter media with a leading edge of said sheet abutting a trailing edgeof said sheet.

2. A method of claim 1 including the step of adding side walls to saidbox-like configuration.

3. A method of making a fluid treating filter comprising the steps of:passing a sheet of metal through a means for expanding a selectedportion of said sheet of metal; cutting said sheet to a configurationhaving two expanded sections and two solid sections, one of said solidsections being disposed between said expanded sections; forming saidsheet into a unitarily constructed topless box-like configurationwhereby one expanded section is a bottom, said solid sections are endwalls, and the other expanded section is an extension of one of the endwalls; adding a selected quantity of filter media to said formed sheet;and, forming a top for the box-like configuration whereby said expandedsection which is an extension of one of the end walls is forced intqahorizontal position to form the top with a leading edge of said sheetabutting a trailing edge of said sheet.

4. A method of claim 3 including the step of adding side walls to saidbox-like configuration.

a m w a

1. A method of making a fluid treating filter comprising the steps of:passing a sheet of metal through a means for expanding a selectedportion of said sheet of metal; cutting said sheet to a desiredconfiguration; adding a selected quantity of filter media to said cutsheet; and forming said sheet into a unitarily constructed box-likeconfiguration, the selected expanded portions of said sheet beingpositioned as a back and front support for said filter media and thenon-expanded portion of said sheet being positioned as end walls forsaid filter media with a leading edge of said sheet abutting a trailingedge of said sheet.
 2. A method of claim 1 including the step of addingside walls to said box-like configuration.
 3. A method of making a fluidtreating filter comprising the steps of: passing a sheet of metalthrough a means for expanding a selected portion of said sheet of metal;cutting said sheet to a configuration having two expanded sections andtwo solid sections, one of said solid sections being disposed betweensaid expanded sections; forming said sheet into a unitarily constructedtopless box-like configuration whereby one expanded section is a bottom,said solid sections are end walls, and the other expanded section is anextension of one of the end walls; adding a selected quantity of filtermedia to said formed sheet; and, forming a top for the box-likeconfiguration whereby said expanded section which is an extension of oneof the end walls is forced into a horizontal position to form the topwith a leading edge of said sheet abutting a trailing edge of saidsheet.
 4. A method of claim 3 including the step of adding side walls tosaid box-like configuration.